JP7055897B2 - Circuit formation method - Google Patents

Description

The present invention relates to a circuit forming method for forming a circuit by making a metal-containing liquid containing metal fine particles and a metal paste containing metal particles and a resin binder conductive.

As described in the following patent documents, techniques for forming a circuit by conducting a metal-containing liquid containing metal fine particles, a metal paste containing metal particles and a resin binder, and the like have been developed.

Japanese Unexamined Patent Publication No. 2004-146694 Japanese Unexamined Patent Publication No. 2011-243870

It is an object of the present invention to appropriately form a circuit by making a metal-containing liquid containing metal fine particles and a metal paste containing metal particles and a resin binder conductive.

In order to solve the above problems, the present specification describes a wiring forming step of linearly applying a metal-containing liquid containing metal fine particles and heating the metal to form a wiring, and a cavity that exposes a part of the wiring. In the base forming step of forming the base having the above metal on the wiring, the metal-containing liquid is linearly applied onto the base so as to reach the inside of the cavity, and the metal particles and resin larger than the metal fine particles are applied. A coating step of applying a metal paste containing a binder to the inside of the cavity so as to overlap the metal- containing liquid, and heating the metal-containing liquid and the metal paste applied in the coating step to make the metal conductive. Disclosed is a circuit forming method including a heating step for causing the metal.

According to the present disclosure, a metal-containing liquid containing metal fine particles and a metal paste containing metal particles are collectively heated to be made conductive. As a result, the metal-containing liquid and the metal paste can be made conductive to form a circuit appropriately.

It is a figure which shows the circuit forming apparatus. It is a block diagram which shows the control device. It is sectional drawing which shows the circuit in the state which the resin laminate is formed. It is sectional drawing which shows the circuit in the state which the wiring is formed on the resin laminate. It is sectional drawing which shows the circuit in the state which the metal paste is discharged on the wiring. It is sectional drawing which shows the circuit in the state which the electronic component is attached. It is sectional drawing which shows the circuit in the state which the metal paste is ejected on the metal ink. It is sectional drawing which shows the circuit in the state which the electronic component is attached. It is a schematic diagram which shows the wiring and metal paste at the time of resistance value measurement. It is sectional drawing which shows the circuit in the state which the wiring is formed on the resin laminate. It is sectional drawing which shows the circuit in the state which the resin laminate is further formed on the resin laminate. It is sectional drawing which shows the circuit in the state which the metal ink is ejected on the resin laminate. It is sectional drawing which shows the circuit in the state which the metal paste is discharged into the cavity of the resin laminate.

First Example FIG. 1 shows a circuit forming apparatus 10. The circuit forming device 10 includes a transport device 20, a first modeling unit 22, a second modeling unit 24, a mounting unit 26, and a control device (see FIG. 2) 28. The transfer device 20, the first modeling unit 22, the second modeling unit 24, and the mounting unit 26 are arranged on the base 29 of the circuit forming device 10. The base 29 has a generally rectangular shape, and in the following description, the longitudinal direction of the base 29 is orthogonal to the X-axis direction, and the lateral direction of the base 29 is orthogonal to both the Y-axis direction, the X-axis direction, and the Y-axis direction. The direction will be referred to as a Z-axis direction.

The transport device 20 includes an X-axis slide mechanism 30 and a Y-axis slide mechanism 32. The X-axis slide mechanism 30 has an X-axis slide rail 34 and an X-axis slider 36. The X-axis slide rail 34 is arranged on the base 29 so as to extend in the X-axis direction. The X-axis slider 36 is slidably held in the X-axis direction by the X-axis slide rail 34. Further, the X-axis slide mechanism 30 has an electromagnetic motor (see FIG. 2) 38, and the X-axis slider 36 moves to an arbitrary position in the X-axis direction by driving the electromagnetic motor 38. Further, the Y-axis slide mechanism 32 has a Y-axis slide rail 50 and a stage 52. The Y-axis slide rail 50 is arranged on the base 29 so as to extend in the Y-axis direction, and is movable in the X-axis direction. Then, one end of the Y-axis slide rail 50 is connected to the X-axis slider 36. The stage 52 is slidably held in the Y-axis slide rail 50 in the Y-axis direction. Further, the Y-axis slide mechanism 32 has an electromagnetic motor (see FIG. 2) 56, and the stage 52 is moved to an arbitrary position in the Y-axis direction by driving the electromagnetic motor 56. As a result, the stage 52 moves to an arbitrary position on the base 29 by driving the X-axis slide mechanism 30 and the Y-axis slide mechanism 32.

The stage 52 has a base 60, a holding device 62, and an elevating device 64. The base 60 is formed in a flat plate shape, and a substrate is placed on the upper surface. The holding devices 62 are provided on both sides of the base 60 in the X-axis direction. Then, both edges of the substrate mounted on the base 60 in the X-axis direction are sandwiched by the holding device 62, so that the substrate is fixedly held. Further, the elevating device 64 is arranged below the base 60 and raises and lowers the base 60.

The first modeling unit 22 is a unit for modeling wiring on a substrate mounted on a base 60 of a stage 52, and has a first printing unit 72 and a heating unit 74. The first printing unit 72 has an inkjet head (see FIG. 2) 76 and a dispense head (see FIG. 2) 77. The inkjet head 76 ejects metal ink linearly. Metal ink is nanometer-sized metal fine particles dispersed in a solvent. Further, the surface of the metal fine particles is coated with a dispersant to prevent aggregation in the solvent. The inkjet head 76 ejects metal ink from a plurality of nozzles by, for example, a piezo method using a piezoelectric element.

Further, the dispense head 77 discharges the metal paste. The metal paste is a resin in which micrometer-sized metal particles are dispersed in a resin that is cured by heating. By the way, the metal particles are in the form of flakes. Since the viscosity of the metal paste is relatively high as compared with the metal ink, the dispense head 77 ejects the metal paste from one nozzle having a diameter larger than the nozzle diameter of the inkjet head 76.

The heating unit 74 has a heater (see FIG. 2) 78. The heater 78 is a device that heats the metal ink ejected by the inkjet head 76. The metal ink is fired by being heated by the heater 78, and wiring is formed. In the firing of metal ink, the solvent is vaporized and the protective film of the metal fine particles, that is, the dispersant is decomposed by applying energy, and the metal fine particles are brought into contact with each other or fused to be conductive. This is a phenomenon in which the rate increases. Then, by firing the metal ink, a metal wiring is formed. The heater 78 is also a device that heats the metal paste discharged by the dispense head 77. The metal paste is heated by the heater 78 to cure the resin. At this time, in the metal paste, the cured resin shrinks, and the flake-shaped metal particles dispersed in the resin come into contact with each other. As a result, the metal paste develops conductivity.

Further, the second modeling unit 24 is a unit for modeling a resin layer on a substrate placed on a base 60 of a stage 52, and has a second printing unit 84 and a curing unit 86. The second printing unit 84 has an inkjet head (see FIG. 2) 88, and the inkjet head 88 ejects an ultraviolet curable resin. The ultraviolet curable resin is a resin that is cured by irradiation with ultraviolet rays. The inkjet head 88 may be, for example, a piezo method using a piezoelectric element, or a thermal method in which a resin is heated to generate bubbles and discharged from a plurality of nozzles.

The cured portion 86 has a flattening device (see FIG. 2) 90 and an irradiation device (see FIG. 2) 92. The flattening device 90 flattens the upper surface of the ultraviolet curable resin ejected by the inkjet head 88. For example, the surplus resin is scraped off by a roller or a blade while leveling the surface of the ultraviolet curable resin. Then, make the thickness of the UV curable resin uniform. Further, the irradiation device 92 includes a mercury lamp or an LED as a light source, and irradiates the discharged ultraviolet curable resin with ultraviolet rays. As a result, the discharged ultraviolet curable resin is cured and a resin layer is formed.

Further, the mounting unit 26 is a unit for mounting electronic components on a substrate mounted on a base 60 of a stage 52, and has a supply unit 110 and a mounting unit 112. The supply unit 110 has a plurality of tape feeders (see FIG. 2) 114 for feeding the taped electronic components one by one, and supplies the electronic components at the supply position. The supply unit 110 is not limited to the tape feeder 114, and may be a tray-type supply device that picks up and supplies electronic components from the tray. Further, the supply unit 110 may be configured to include both a tape type and a tray type, or other supply devices.

The mounting unit 112 has a mounting head (see FIG. 2) 116 and a moving device (see FIG. 2) 118. The mounting head 116 has a suction nozzle (not shown) for sucking and holding electronic components. The suction nozzle sucks and holds electronic components by sucking air by supplying negative pressure from a positive / negative pressure supply device (not shown). Then, when a slight positive pressure is supplied from the positive / negative pressure supply device, the electronic component is separated. Further, the moving device 118 moves the mounting head 116 between the supply position of the electronic component by the tape feeder 114 and the substrate mounted on the base 60. As a result, in the mounting unit 112, the electronic component supplied from the tape feeder 114 is held by the suction nozzle, and the electronic component held by the suction nozzle is mounted on the substrate.

Further, as shown in FIG. 2, the control device 28 includes a controller 120 and a plurality of drive circuits 122. The plurality of drive circuits 122 include the electromagnetic motors 38 and 56, a holding device 62, an elevating device 64, an inkjet head 76, a dispense head 77, a heater 78, an inkjet head 88, a flattening device 90, an irradiation device 92, and a tape feeder 114. It is connected to the mounting head 116 and the moving device 118. The controller 120 includes a CPU, ROM, RAM, etc., and is mainly a computer, and is connected to a plurality of drive circuits 122. As a result, the operation of the transfer device 20, the first modeling unit 22, the second modeling unit 24, and the mounting unit 26 is controlled by the controller 120.

In the circuit forming apparatus 10, a resin laminate is formed on a substrate (see FIG. 3) 70 by the above-described configuration, and metal ink is printed on the upper surface of the resin laminate according to a circuit pattern. The metal ink is made conductive by heating, and wiring is formed. Then, the electrodes of the electronic components are connected to the wiring, and the electrodes of the electronic components are connected to the wiring via the metal paste in order to improve the adhesion between the resin laminate and the wiring. The metal paste is also made conductive by heating, and the electronic components and the wiring are electrically conductive. In this way, wiring is formed on the resin laminate, and electronic components are electrically connected to the wiring to form a circuit. However, in the conventional method, the metal ink is heated at the time of wiring formation. Furthermore, the metal paste is also heated to conduct with the electronic components and the wiring. That is, the metal ink and the metal paste are heated individually. At this time, since the resin laminate is also heated, it expands and contracts due to the heat load on the resin laminate, and fatigue accumulates in the resin laminate, which may cause mechanical deterioration and destruction.

Specifically, the substrate 70 is set on the base 60 of the stage 52, and the stage 52 is moved below the second modeling unit 24. Then, in the second modeling unit 24, as shown in FIG. 3, the resin laminate 130 is formed on the substrate 70. The resin laminate 130 is formed by repeatedly ejecting an ultraviolet curable resin from the inkjet head 88 and irradiating the ejected ultraviolet curable resin with ultraviolet rays by an irradiation device 92.

Specifically, in the second printing unit 84 of the second modeling unit 24, the inkjet head 88 ejects the ultraviolet curable resin into a thin film on the upper surface of the substrate 70. Subsequently, when the ultraviolet curable resin is discharged in the form of a thin film, the ultraviolet curable resin is flattened by the flattening device 90 so that the film thickness of the ultraviolet curable resin becomes uniform in the cured portion 86. Then, the irradiation device 92 irradiates the thin-film ultraviolet curable resin with ultraviolet rays. As a result, the thin film-shaped resin layer 132 is formed on the substrate 70.

Subsequently, the inkjet head 88 ejects the ultraviolet curable resin into a thin film on the thin film resin layer 132. Then, the thin-film ultraviolet-curable resin is flattened by the flattening device 90, and the irradiation device 92 irradiates the ultraviolet-curable resin discharged in the thin-film form with ultraviolet rays on the thin-film resin layer 132. The thin-film resin layer 132 is laminated. In this way, the ejection of the ultraviolet curable resin onto the thin-film resin layer 132 and the irradiation of ultraviolet rays are repeated, and the plurality of resin layers 132 are laminated to form the resin laminate 130.

When the resin laminate 130 is formed by the procedure described above, the stage 52 is moved below the first modeling unit 22. Then, in the first printing unit 72 of the first modeling unit 22, the inkjet head 76 linearly ejects the metal ink 134 onto the upper surface of the resin laminate 130 according to the circuit pattern, as shown in FIG. Subsequently, in the heating unit 74 of the first modeling unit 22, the metal ink 134 ejected according to the circuit pattern is heated by the heater 78. As a result, the metal ink 134 is fired, and the wiring 136 is formed on the resin laminate 130. The heating temperature set for firing the metal ink 134 is 120 ° C., and the heating time is 1 hour. Therefore, when the metal ink 134 is fired, the metal ink 134 is heated by the heater 78 at 120 ° C. for 1 hour.

Subsequently, when the wiring 136 is formed by firing the metal ink 134, in the first printing portion 72 of the first modeling unit 22, the dispense head 77 is placed on the end portion of the wiring 136 as shown in FIG. Discharge the metal paste 137. As described above, when the metal paste 137 is discharged onto the wiring 136, the stage 52 is moved below the mounting unit 26. In the mounting unit 26, the electronic component 138 is supplied by the tape feeder 114, and the electronic component 138 is held by the suction nozzle of the mounting head 116. As shown in FIG. 6, the electronic component 138 is composed of a component body 139 and two electrodes 140 arranged on the lower surface of the component body 139. Then, the mounting head 116 is moved by the moving device 118, and the electronic component 138 held by the suction nozzle is mounted on the upper surface of the resin laminate 130. At this time, the electronic component 138 is mounted on the upper surface of the resin laminate 130 so that the electrode 140 of the electronic component 138 comes into contact with the metal paste 137 discharged on the wiring 136.

Next, when the electronic component 138 is mounted, the stage 52 is moved below the first modeling unit 22. Then, in the heating unit 74 of the first modeling unit 22, the metal paste 137 is heated by the heater 78. As a result, the metal paste 137 becomes conductive, so that the electrode 140 conducts with the wiring 136 via the metal paste 137, and a circuit is formed. The heating temperature set for making the metal paste 137 conductive is 150 ° C., and the heating time is 1 hour and 10 minutes. Therefore, when the metal paste 137 is made conductive, the metal paste 137 is heated by the heater 78 at 150 ° C. for 1 hour and 10 minutes.

However, in the above method, when the metal ink 134 is fired, the metal ink 134 is heated at 120 ° C. for 1 hour by the heater 78, and when the metal paste 137 is made conductive, the metal paste 137 is heated at 150 ° C. for 1 hour and 10 minutes. , Heated by the heater 78. At this time, since the resin laminate 130 is heated by the heater 78 at a high temperature of 120 to 150 ° C. for a total of 2 hours and 10 minutes, the resin laminate 130 may be mechanically deteriorated or destroyed.

In view of this, in the circuit forming apparatus 10, the metal ink 134 and the metal paste 137 are heated together, and the metal ink 134 is fired and the metal paste 137 is made conductive at the same time. That is, in the conventional method, the metal ink 134 and the metal paste 137 are individually heated, but in the circuit forming apparatus 10, the metal ink 134 and the metal paste 137 are heated at the same time.

Specifically, when the resin laminate 130 is formed, the inkjet head 76 ejects the metal ink 134 on the upper surface of the resin laminate 130 according to the circuit pattern in the first printing unit 72 of the first modeling unit 22. .. However, at this timing, the metal ink 134 is not heated, and as shown in FIG. 7, the metal paste 137 is ejected onto the metal ink 134 by the dispense head 77.

In this way, when the metal paste 137 is ejected onto the unheated metal ink 134, the stage 52 is moved below the mounting unit 26. Then, in the mounting unit 26, the electronic component 138 is mounted on the upper surface of the resin laminate 130 so that the electrode 140 comes into contact with the metal paste 137, as shown in FIG. At this time, the metal ink 134 and the metal paste 137 are not heated and are not conductive.

Subsequently, when the electronic component 138 is mounted on the upper surface of the resin laminate 130, the stage 52 is moved below the first modeling unit 22. Then, in the heating unit 74 of the first modeling unit 22, the metal ink 134 and the metal paste 137 ejected onto the metal ink 134 are heated by the heater 78. That is, the metal ink 134 and the metal paste 137 are heated together. At this time, the metal ink 134 is fired to form the wiring 136, and the metal paste 137 becomes conductive. As a result, the electrode 140 of the electronic component 138 conducts with the wiring 136 via the metal paste 137, and a circuit is formed. The heating temperature and heating time when the metal ink 134 and the metal paste 137 are collectively heated are among the heating temperature and heating time when the resin laminate 130 and the metal ink 134 are individually heated. It is said to have a high heating temperature and a long heating time. Therefore, the metal ink 134 and the metal paste 137 are collectively heated by the heater 78 at 150 ° C. for 1 hour and 10 minutes.

By heating the metal ink 134 and the metal paste 137 together in this way, the heating time by the heater 78 at the time of circuit formation is 1 hour and 10 minutes. That is, in the conventional method, the resin laminate 130 was heated by the heater 78 for 2 hours and 10 minutes, but in this method, the resin laminate 130 is heated by the heater 78 for only about 1 hour and 10 minutes, which is about half of the conventional method. Not heated by. This makes it possible to reduce the damage of the resin laminate 130 and suppress the occurrence of mechanical deterioration, breakage, etc. of the resin laminate 130. Further, since the heating time by the heater 78 is shortened by one hour, the time required for circuit formation is also shortened. As a result, it is possible not only to suppress the occurrence of mechanical deterioration and destruction of the resin laminate 130, but also to shorten the cycle time.

Furthermore, the heating temperature and heating time when the metal ink 134 and the metal paste 137 are collectively heated are the heating temperatures and heating times when the resin laminate 130 and the metal ink 134 are individually heated. It is said to have a high heating temperature and a long heating time. As a result, the metal ink 134 can be appropriately fired and the metal paste 137 can be appropriately made conductive.

However, when the metal ink 134 and the metal paste 137 are heated together, the metal paste 137 is ejected onto the metal ink 134, so that the metal ink 134 located below the metal paste 137 is fired. I am concerned. Therefore, the resistance value when the metal ink 134 and the metal paste 137 were individually heated and the resistance value when the metal ink 134 and the metal paste 137 were heated together were measured.

Specifically, as shown in FIG. 9, in order to measure the resistance value when the metal ink 134 and the metal paste 137 are individually heated, the inkjet head 76 is such that the metal ink 134 draws two lines. And heated by the heater 78 at 120 ° C. for 1 hour. As a result, two wirings 136 are formed. The two wirings 136 are located on a straight line, and the distance between the ends thereof is 250 μm. Then, after the two wires 136 are formed, the metal paste 137 is discharged by the dispense head 77 so as to connect the two wires 136. Incidentally, the discharged metal paste 137 has a circular shape with an outer diameter of 600 μm. Then, the metal paste 137 is heated by the heater 78 at 150 ° C. for 1 hour and 10 minutes to make it conductive. In this way, the metal ink 134 and the metal paste 137 are individually heated, so that the two wirings 136 are electrically energized by the metal paste 137. Then, the resistance value of the metal paste 137 at the time of power supply to those two wirings 136 was measured and found to be about 0.05Ω. That is, the resistance value when the metal ink 134 and the metal paste 137 are individually heated is about 0.05 Ω.

Further, in order to measure the resistance value when the metal ink 134 and the metal paste 137 are heated together, the metal ink 134 measures the resistance value when the metal ink 134 and the metal paste 137 are individually heated. It is ejected so as to draw two lines as in the case of. Next, the metal paste 137 is ejected so as to connect the two linearly ejected metal inks 134 without heating the metal ink 134. At this time, the metal paste 137 is ejected in the same manner as when measuring the resistance value when the metal ink 134 and the metal paste 137 are individually heated. Then, the metal ink 134 and the metal paste 137 are collectively heated at 150 ° C. for 1 hour and 10 minutes by the heater 78, so that the metal ink 134 is fired and the metal paste 137 becomes conductive. In this way, the metal ink 134 and the metal paste 137 are heated together, so that the two wirings 136 are electrically energized by the metal paste 137. Then, when the resistance value of the metal paste 137 at the time of power supply to those two wirings 136 was measured, it was about 0.15Ω. That is, the resistance value when the metal ink 134 and the metal paste 137 are heated together is about 0.15 Ω.

As described above, the resistance value (about 0.15 Ω) when the metal ink 134 and the metal paste 137 are heated together is the resistance value (about 0.15 Ω) when the metal ink 134 and the metal paste 137 are individually heated. It is about 0.1Ω higher than 0.05Ω). However, the increase in resistance value to that extent is not large in practical use as compared with the wiring resistance. Therefore, even a circuit formed by heating the metal ink 134 and the metal paste 137 together can be used without any problem.

Second Example In the first embodiment, the electronic component 138 is electrically connected to the wiring 136 via the metal paste 137, but in the second embodiment, the electronic component 138 is formed on a different resin laminate. The wiring of the book is electrically connected by the metal paste. Specifically, in the first modeling unit 22, as shown in FIG. 10, the metal ink 134 is linearly ejected onto the resin laminate 130 by the inkjet head 76, and the metal ink 134 is linearly ejected by the heater 78 at 120 ° C. It is heated for 1 hour. As a result, the wiring 136 is formed on the resin laminate 130.

Next, in the second modeling unit 24, as shown in FIG. 11, the resin laminate 150 is formed on the resin laminate 130. Since the resin laminate 150 is formed by a method substantially similar to that of the resin laminate 130, the description of the method for forming the resin laminate 150 will be omitted. However, the cavity 152 is formed in the resin laminate 150, and the end portion of the wiring 136 is exposed through the cavity 152.

Subsequently, in the first modeling unit 22, as shown in FIG. 12, the metal ink 154 is linearly ejected onto the resin laminate 150 by the inkjet head 76. The metal ink 154 is ejected to the inside of the cavity 152, although the end portion does not reach the bottom surface of the cavity 152. Then, the metal paste 137 is ejected into the inside of the cavity 152 by the dispense head 77 without heating the metal ink 154. At this time, as shown in FIG. 13, the metal paste 137 is discharged into the inside of the cavity 152 up to the upper edge of the cavity 152. Therefore, the metal paste 137 comes into contact with the metal ink 134 at the lower end portion and comes into contact with the metal ink 154 at the upper end portion.

Then, when the metal ink 154 and the metal paste 137 are ejected, the metal ink 154 and the metal paste 137 are collectively heated by the heater 78 at 150 ° C. for 1 hour and 10 minutes. At this time, the metal ink 154 is fired to form the wiring 156, and the metal paste 137 becomes conductive. As a result, the wiring 136 formed on the resin laminate 130 and the wiring 156 formed on the resin laminate 150 are electrically connected via the metal paste 137.

As described above, even when the two wirings 136 and 156 formed on the different resin laminates 130 and 150 are electrically connected by the metal paste 137, the metal ink 154 and the metal paste 137 are collectively connected. Be heated. As a result, it is possible to suppress the occurrence of mechanical deterioration, breakage, etc. of the resin laminate 150, and to shorten the cycle time.

As shown in FIG. 2, the controller 120 of the control device 28 has a base forming portion 160, a coating portion 162, and a heating portion 164. The base forming portion 160 is a functional part for forming the resin laminated body 130 in the first embodiment, and is a functional part for forming the resin laminated body 150 in the second embodiment. The coating unit 162 is a functional unit for applying the metal ink 134 and the metal paste 137 in the first embodiment, and is a functional unit for applying the metal ink 154 and the metal paste 137 in the second embodiment. .. The heating unit 164 is a functional unit for collectively heating the metal ink 134 and the metal paste 137 in the first embodiment, and is for collectively heating the metal ink 154 and the metal paste 137 in the second embodiment. It is a functional part.

In the above embodiment, the resin laminates 130 and 150 are examples of the base. The resin layer 132 is an example of the resin layer. The metal inks 134 and 154 are examples of metal-containing liquids. The metal paste 137 is an example of a metal paste. The process executed by the base forming unit 160 is an example of the base forming process. The step executed by the coating unit 162 is an example of the coating process. The step executed by the heating unit 164 is an example of the heating step.

The present invention is not limited to the above embodiment, and can be carried out in various embodiments with various changes and improvements based on the knowledge of those skilled in the art. For example, in the above embodiment, the metal ink 134, the metal paste 137, etc. are heated by the heater 78, but the metal ink 134, the metal paste 137, etc. may be heated by irradiation with laser light or the like.

Further, in the above embodiment, the metal ink 134 contains nanometer-sized metal fine particles and the metal paste 137 contains micrometer-sized metal particles, but the particle size can be arbitrarily set. .. However, it is preferable that the metal ink 134, which is the material of the wiring 136, contains metal fine particles smaller than the metal particles contained in the metal paste 137.

Further, in the above embodiment, the metal paste 137 is discharged to the resin laminate 130 by the dispense head 77, but the metal paste 137 may be transferred to the resin laminate 130 by a stamp or the like. Further, the metal paste 137 may be printed on the resin laminate 130 by screen printing.

130: Resin laminate (base) 132: Resin layer 134: Metal ink (metal-containing liquid) 137: Metal paste 150: Resin laminate (base) 154: Metal ink (metal-containing liquid) 160: Base forming portion (base formation) Process) 162: Coating part (coating process) 164: Heating part (heating process)

Claims (4)

A wiring forming process in which a metal-containing liquid containing metal fine particles is linearly applied and heated to form wiring.
A base forming step of forming a base having a cavity for exposing a part of the wiring on the wiring,
The metal-containing liquid is linearly applied onto the base so as to reach the inside of the cavity, and a metal paste containing metal particles larger than the metal fine particles and a resin binder is overlapped with the metal-containing liquid . The application process of applying to the inside of the cavity and
A circuit forming method including a heating step of heating the metal-containing liquid coated in the coating step and the metal paste to make them conductive. The circuit forming method according to claim 1, further comprising the base forming step of forming the base by forming a resin layer by applying a curable resin in a thin film form and laminating the resin layers. The heating step is
Due to the higher heating temperature and longer heating time of the heating temperature and heating time set to make the metal-containing liquid conductive and the heating temperature and heating time set to make the metal paste conductive. The circuit forming method according to claim 1 or 2 , wherein the metal-containing liquid and the metal paste are made conductive by heating. The metal-containing liquid contains nanometer-sized metal fine particles.
The circuit forming method according to any one of claims 1 to 3 , wherein the metal paste contains metal particles having a micrometer size.

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